xref: /linux/drivers/platform/x86/intel/tpmi_power_domains.c (revision 903a7d37d9ea03cfed21040467d3d345d1e6fc76)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Mapping of TPMI power domains CPU mapping
4  *
5  * Copyright (c) 2024, Intel Corporation.
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/cleanup.h>
10 #include <linux/cpuhotplug.h>
11 #include <linux/cpumask.h>
12 #include <linux/errno.h>
13 #include <linux/export.h>
14 #include <linux/hashtable.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/overflow.h>
18 #include <linux/slab.h>
19 #include <linux/topology.h>
20 #include <linux/types.h>
21 
22 #include <asm/cpu_device_id.h>
23 #include <asm/intel-family.h>
24 #include <asm/msr.h>
25 
26 #include "tpmi_power_domains.h"
27 
28 #define MSR_PM_LOGICAL_ID       0x54
29 
30 /*
31  * Struct of MSR 0x54
32  * [15:11] PM_DOMAIN_ID
33  * [10:3] MODULE_ID (aka IDI_AGENT_ID)
34  * [2:0] LP_ID
35  * For Atom:
36  *   [2] Always 0
37  *   [1:0] core ID within module
38  * For Core
39  *   [2:1] Always 0
40  *   [0] thread ID
41  */
42 
43 #define LP_ID_MASK		GENMASK_ULL(2, 0)
44 #define MODULE_ID_MASK		GENMASK_ULL(10, 3)
45 #define PM_DOMAIN_ID_MASK	GENMASK_ULL(15, 11)
46 
47 /**
48  * struct tpmi_cpu_info - Mapping information for a CPU
49  * @hnode: Used to add mapping information to hash list
50  * @linux_cpu:	Linux CPU number
51  * @pkg_id: Package ID of this CPU
52  * @punit_thread_id: Punit thread id of this CPU
53  * @punit_core_id: Punit core id
54  * @punit_domain_id: Power domain id from Punit
55  *
56  * Structure to store mapping information for a Linux CPU
57  * to a Punit core, thread and power domain.
58  */
59 struct tpmi_cpu_info {
60 	struct hlist_node hnode;
61 	int linux_cpu;
62 	u8 pkg_id;
63 	u8 punit_thread_id;
64 	u8 punit_core_id;
65 	u8 punit_domain_id;
66 };
67 
68 static DEFINE_PER_CPU(struct tpmi_cpu_info, tpmi_cpu_info);
69 
70 /* The dynamically assigned cpu hotplug state to free later */
71 static enum cpuhp_state tpmi_hp_state __read_mostly;
72 
73 #define MAX_POWER_DOMAINS	8
74 
75 static cpumask_t *tpmi_power_domain_mask;
76 
77 /* Lock to protect tpmi_power_domain_mask and tpmi_cpu_hash */
78 static DEFINE_MUTEX(tpmi_lock);
79 
80 static const struct x86_cpu_id tpmi_cpu_ids[] = {
81 	X86_MATCH_VFM(INTEL_GRANITERAPIDS_X,	NULL),
82 	X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X,	NULL),
83 	X86_MATCH_VFM(INTEL_ATOM_CRESTMONT,	NULL),
84 	X86_MATCH_VFM(INTEL_GRANITERAPIDS_D,	NULL),
85 	X86_MATCH_VFM(INTEL_PANTHERCOVE_X,	NULL),
86 	{}
87 };
88 MODULE_DEVICE_TABLE(x86cpu, tpmi_cpu_ids);
89 
90 static DECLARE_HASHTABLE(tpmi_cpu_hash, 8);
91 
92 static bool tpmi_domain_is_valid(struct tpmi_cpu_info *info)
93 {
94 	return info->pkg_id < topology_max_packages() &&
95 		info->punit_domain_id < MAX_POWER_DOMAINS;
96 }
97 
98 int tpmi_get_linux_cpu_number(int package_id, int domain_id, int punit_core_id)
99 {
100 	struct tpmi_cpu_info *info;
101 	int ret = -EINVAL;
102 
103 	guard(mutex)(&tpmi_lock);
104 	hash_for_each_possible(tpmi_cpu_hash, info, hnode, punit_core_id) {
105 		if (info->punit_domain_id == domain_id && info->pkg_id == package_id) {
106 			ret = info->linux_cpu;
107 			break;
108 		}
109 	}
110 
111 	return ret;
112 }
113 EXPORT_SYMBOL_NS_GPL(tpmi_get_linux_cpu_number, INTEL_TPMI_POWER_DOMAIN);
114 
115 int tpmi_get_punit_core_number(int cpu_no)
116 {
117 	if (cpu_no >= num_possible_cpus())
118 		return -EINVAL;
119 
120 	return per_cpu(tpmi_cpu_info, cpu_no).punit_core_id;
121 }
122 EXPORT_SYMBOL_NS_GPL(tpmi_get_punit_core_number, INTEL_TPMI_POWER_DOMAIN);
123 
124 int tpmi_get_power_domain_id(int cpu_no)
125 {
126 	if (cpu_no >= num_possible_cpus())
127 		return -EINVAL;
128 
129 	return per_cpu(tpmi_cpu_info, cpu_no).punit_domain_id;
130 }
131 EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_id, INTEL_TPMI_POWER_DOMAIN);
132 
133 cpumask_t *tpmi_get_power_domain_mask(int cpu_no)
134 {
135 	struct tpmi_cpu_info *info;
136 	cpumask_t *mask;
137 	int index;
138 
139 	if (cpu_no >= num_possible_cpus())
140 		return NULL;
141 
142 	info = &per_cpu(tpmi_cpu_info, cpu_no);
143 	if (!tpmi_domain_is_valid(info))
144 		return NULL;
145 
146 	index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
147 	guard(mutex)(&tpmi_lock);
148 	mask = &tpmi_power_domain_mask[index];
149 
150 	return mask;
151 }
152 EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_mask, INTEL_TPMI_POWER_DOMAIN);
153 
154 static int tpmi_get_logical_id(unsigned int cpu, struct tpmi_cpu_info *info)
155 {
156 	u64 data;
157 	int ret;
158 
159 	ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
160 	if (ret)
161 		return ret;
162 
163 	info->punit_domain_id = FIELD_GET(PM_DOMAIN_ID_MASK, data);
164 	if (info->punit_domain_id >= MAX_POWER_DOMAINS)
165 		return -EINVAL;
166 
167 	info->punit_thread_id = FIELD_GET(LP_ID_MASK, data);
168 	info->punit_core_id = FIELD_GET(MODULE_ID_MASK, data);
169 	info->pkg_id = topology_physical_package_id(cpu);
170 	info->linux_cpu = cpu;
171 
172 	return 0;
173 }
174 
175 static int tpmi_cpu_online(unsigned int cpu)
176 {
177 	struct tpmi_cpu_info *info = &per_cpu(tpmi_cpu_info, cpu);
178 	int ret, index;
179 
180 	/* Don't fail CPU online for some bad mapping of CPUs */
181 	ret = tpmi_get_logical_id(cpu, info);
182 	if (ret)
183 		return 0;
184 
185 	index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
186 
187 	guard(mutex)(&tpmi_lock);
188 	cpumask_set_cpu(cpu, &tpmi_power_domain_mask[index]);
189 	hash_add(tpmi_cpu_hash, &info->hnode, info->punit_core_id);
190 
191 	return 0;
192 }
193 
194 static int __init tpmi_init(void)
195 {
196 	const struct x86_cpu_id *id;
197 	u64 data;
198 	int ret;
199 
200 	id = x86_match_cpu(tpmi_cpu_ids);
201 	if (!id)
202 		return -ENODEV;
203 
204 	/* Check for MSR 0x54 presence */
205 	ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
206 	if (ret)
207 		return ret;
208 
209 	tpmi_power_domain_mask = kcalloc(size_mul(topology_max_packages(), MAX_POWER_DOMAINS),
210 					 sizeof(*tpmi_power_domain_mask), GFP_KERNEL);
211 	if (!tpmi_power_domain_mask)
212 		return -ENOMEM;
213 
214 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
215 				"platform/x86/tpmi_power_domains:online",
216 				tpmi_cpu_online, NULL);
217 	if (ret < 0) {
218 		kfree(tpmi_power_domain_mask);
219 		return ret;
220 	}
221 
222 	tpmi_hp_state = ret;
223 
224 	return 0;
225 }
226 module_init(tpmi_init)
227 
228 static void __exit tpmi_exit(void)
229 {
230 	cpuhp_remove_state(tpmi_hp_state);
231 	kfree(tpmi_power_domain_mask);
232 }
233 module_exit(tpmi_exit)
234 
235 MODULE_DESCRIPTION("TPMI Power Domains Mapping");
236 MODULE_LICENSE("GPL");
237